It seems that (some) of the Launchpad buildd's don't have epoll support. For example, from https://launchpad.net/~nikratio/+archive/s3ql/+build/5881098:
Traceback (most recent call last):
File "/build/buildd/python-dugong-2.2+dfsg/test/test_aio.py", line 51, in test_aio_future
loop = asyncio.get_event_loop()
File "/usr/lib/python3.4/asyncio/events.py", line 465, in get_event_loop
return get_event_loop_policy().get_event_loop()
File "/usr/lib/python3.4/asyncio/events.py", line 410, in get_event_loop
self.set_event_loop(self.new_event_loop())
File "/usr/lib/python3.4/asyncio/events.py", line 428, in new_event_loop
return self._loop_factory()
File "/usr/lib/python3.4/asyncio/unix_events.py", line 40, in __init__
super().__init__(selector)
File "/usr/lib/python3.4/asyncio/selector_events.py", line 36, in __init__
selector = selectors.DefaultSelector()
File "/usr/lib/python3.4/selectors.py", line 387, in __init__
self._epoll = select.epoll()
OSError: [Errno 38] Function not implemented
!!!!!!!!!!!!!!!!!!!! Interrupted: stopping after 1 failures !!!!!!!!!!!!!!!!!!!!
We recently deployed new virtual builder infrastructure, including running on trusty kernels rather than hardy kernels. That may well fix this bug. However, I tried retrying the build in question and of course it had been superseded by a newer version of the source package in which this test is skipped.
Do you think you could try re-enabling this test and reporting whether it still fails? If it does, we might actually have a chance of fixing that now ...